>>971
sqlserverならこんな感じでできる
select * from (
select m.id ,m.日付,m.値,s.日付 as 最大値日付,row_number (partation by m.id,m.日付　order by m.値 desc)　as 順
from テーブル as m
left join テーブル as s
on s.id = m.id
and s.日付 between deteadd (yy,-1,m.日付) and m.日付
) as mm
where 順　=　1